Telephone system



Dec.v 7, 1937. F. A. KORN TELEPHONE SYSTEM Filed March 11, 1936 5 SheetsS heet l 02 x23 wg zoiadm T to. xmmmo 09 QOk UZDE MGKQMM Gad wokuzbwmwmk o2 m kko u Nut GR INVENTOR EA. KORN A TTOR/VEY V Deg. 7, 1937.

F. A. KORN TELEPHONE SYSTEM Filed March 11, 1956 ssheets-shet 2 ATTORNEY Dec. 7, 1937. F. A. KORN TELEPHONE SYSTEM Filed March '11,

1936 3 Sheets-Sheet 5 m i; 5 U

9mm QQRUEDB RED 0? QQm QQRUEDS QECGMIQ QWQSDZ INVENTOR FJLKORN A Tram/5y Patented Dec. 7, 1937 UNITED STATES PATENT OFFICE Bell Telephone Laboratories,

Incorporated,

New York, N. Y., a corporation of New York Application March 11, 1936, Serial No. 68,255

9 Claims.

This invention relates to telephone systems and has for its object to facilitate the control of special service calls in such systems.

In telephone systems there are a number of conditions under which an operator desires access to a subscribers line but does not need to signal or converse with the subscriber himself. For example, in the extension of toll calls, the operator wishes to check the accuracy of the calling line number as given her by the calling subscriber. Likewise an operator may wish to verify a busy condition, or the test desk may Wish to connect with an apparently busy line to determine the cause of trouble.

In the cross-bar system such calls require a considerable amount of additional apparatus in the control equipment or marker and it is desirable to add this apparatus to only a limited number of markers. However, the registering equipment or senders and the. connectors for connecting them with the trunks and markers are common to service trunks as well as to the special trunks used in the calls above discussed. Therefore, in accordance with the present invention, means is provided whereby the seizure of registering and connecting equipment by a special trunk permits them to be connected to specially.

equipped control equipment only. More specifically, the special trunks are arranged to indicate to the sender that a special trunk is calling, which in turn relays the signal to the marker connector. The marker connector places an artificial busy condition on all markers except those equipped for special service, which busy condition appears only to the marker connector applying it. It then tests for an idle special marker and connects with the latter. The selected marker, in controlling connections establishes a second connection with the incoming trunk, independent of the sender and receives over this connection a signal which discriminates between the various special trunks.

For a complete disclosure of a cross-bar system for establishing regular as well as these special calls, reference is made to the application of W. W. Carpenter, Serial No. 68,262, filed March 11, 1936.

The. invention will be more clearly understood from a consideration of the following description, read in connection with the drawings in which:

Fig. 1 shows portions of a service junctor, a no-test junctor, a sender link, a B sender, and a B operators position;

Fig. 2 shows portions of a marker connector, an incoming frame connector and a marker ,2

Fig. 3 shows portions of a number checking junctor and a no-hunt junctor; and

Fig. 4 shows the manner of arranging Figs. 1 to 3.

In the drawings, for the sake. of simplicity, the 5 four types of trunks are represented as appearing on the same frame, although such an arrange ment might not be used in practice.

When any one junctor is seized, it grounds a start conductor leading toward the sender link which operates a primary and a secondary sender selector to connect the junctor with an idle sender. The sender hunts for an idle B operators position and connects it through to the calling party. The designation of the wanted 15 line is passed tothe B operator who sets it up on her key-set, thereby recording it on sender registers. The sender then causes the marker connector to connect the sender with a marker to which the designation is transmitted. The marker translates the designation and connects with the group of lines or choice within which the Wanted line lies. Having obtained access to the desired choice, the marker operates the incoming connector which has access to the incoming 25 frame carrying the calling junctor and then proceeds to function to complete the desired connection.

More specifically, when the service junctor I00 is seized, relay illI operates, closing a circuit from 0 round over its front contact, back contact of relay IIJZ to start conductor I03 which initiates the operation of the sender link I30. The link closes cross-points I3I and I 32 connecting the junctor It!!! to the sender Mil. It also operates relay I33 35 which is individual to the frame on which the junctor and link are located, setting up a registration on the frame register I M of the sender. The frame register relays operate relay I42 which closes a circuit from ground over the back contact of relay I43, front contact of relay I42, contacts of cross-points I32 and I3I, to the winding of relay I02 and battery. Relay I02 locks under the control of relay IOI, opens the start lead and prepares the circuit of relay IM. The circuit of 45 relay I 02 passes through equipment in the sender (not shown) which causes the operation of relay, I43 and the opening of the operating circuit of relay I02.

The frame register also initiates the search for an idle operators position and when one is found, for example position I44, relay I is operated connecting that position over the tip and ring contacts of cross-points I32 and I3I to-the tip andring conductors of the junctor I00. The 5 usual zip tones are transmitted, the wanted number given and recorded, after which battery is connected to start conductor I43 to summon when the associated marker is busy. Therefore,

if the relay is released, indicating that the marker is idle, a circuit is completed over the back contact of relay 20'! to the winding of relay 208 and ground. Relay 238 in turn operates multi-contact relay 200 which completes the connection between the sender and the correspondingmarker. Assuming'only the last marker is idle, the circuit extends'over the frontcontacts of relays 201, 2I2 and intermediate relays to the back contact of relay 2I3, winding of relay 2! 4 and ground. Relay 2I4 operates multi-contact relay 2I5 to connect sender I40 with marker 220.

The registration set up in the sender together With the frame registration is transferred to the marker. The marker then selects the choice Within which the Wanted line lies and then, under the. control of frame register 22I operates relay 23I which is individual to the marker 220 in the incoming frame connector 230 individual to the frame on which incoming junctor I00 is located. Relay 23I in turn operates relay 222, which connects ground through the marker connector to conductor 2I0, lower contacts of crosspoints I3I and I32, winding of relay I05 and battery. Relay I05 extends the outgoing tip and ring conductors and certain other conductors (not shown) to the incoming frame connector and operates relay 232 which is individual to the group of ten junctors, appearing in the same primary incoming selector, of which the junctor I00 is one. Relay 232 further extends the conductors closed by relay I05 to the Nos. 4 and 5 contacts of relay 23I which completes their connection into the marker 220. The marker now proceeds to control the establishment of the desired connection, the operation progressing in the normal manner since junctor I00 is a subscribers or service junctor.

When a call is extended to the no-test junctor I20, the sleeve relay I2I grounds the start lead I23 over the back contact of relay I22. The sender link I30 connects the junctor I20 over cross-points I34 and I32 with sender I40, or any other idle sender. As soon as these cross-points close, a circuit is completed from ground over the back contact of relay I22, lower contacts of cross-po nts I34 and I32, right back contact of relay I43, left winding of relay I41 and battery. Relay I41 locks under the control of relay I48 which operates as soon as the connection between the sender and junctor is complete. Relay I41 immediately grounds conductor I49. When relay 20I operates to connect the sender with the cross-wires of the marker connector, conductor I43 is extended over the outer lower contact of relay 20I, winding of relay 2I I, inner lower contact of relay 20I to battery on conductor I46. Relay 2II connects ground to the right winding of relay 201 and to the corresponding windings of all sim lar relays in this marker connector indiv dual to markers equipped to handle only service calls, thereby making all such ma kers busy to this marker connector if idle and holding busy any which might become idle. The markers are multipled before other marker conhectors, and an actual busy condition is recorded in all marker connectors. This special busy condition, however, is applied only to this marker connector maldng the call. When multi-contact relay 203 extends the battery connected to conductor I46 to the armature of relay 201, the circult is extended over the front contact of that relay and of the intermediate relays belonging to service markers, to the armature of relay 2l2 associated with the first special marker. Assuming that marker to be busy, the circuit extends to the winding of relay 2 I4 and the sender is connected to marker 220.

With relay 2 operated, 'the operation of multi-contact relay 2I5 closes a circuit from ground over the inner right contact of relay 2I I, contact of relay 2I5, winding of relay 223 and battery. This relayindicates t0 the marker that it is to handle a special type of call and the line selecting circuit is opened to delay the functioning of the marker until the exact type of call has been determined. Otherwise the marker functions in the usual manner until connected to the junctor by the frame connector.

When the sender relay I42 operates, relay I22 is operated disconnecting the special marking -groundfrom the lower contacts of the crossnection is desired. For a description of the func- 'tioning of the marker in connection with such a call, reference may be made to Patent 2,075,527, granted March 30, 1937 to F. A. Korn et al.

In the case of a number checking call employing junctor 300, the seizure of the trunk operates relay 30I which grounds conductor 303 to initiate the operation of the sender link. As soon as cross-points I35 and I32 have been closed, ground over the back contact of relay 302 operates relay I41 which functions as previously described to seize a special marker and operate relay 223 in the marker. When sender relay I42 operates, relay 302 operates, opening this special marking ground. When the marker has operated relay 23I in the incoming frame connector, relay 305 is operated over the front contact of relay 302. Relay 305 operates relay 234 which completes the connection between junctor 300 and the marker 220. In number checking, no talking circuit is required, and therefore relays 305 and 234 do not close through any talking conductors. Relay 305 connects ground over its inner contact, N0. 2 lower contact of relay 23I, middle contact of relay 223, winding of relay 225 and battery. Relay 225 prepares the marker for handling a number checking call which takes place as described in the application of F. A. Korn, Serial No. 68,256,

'filed March 11, 1936.

The fourth type of junctor shown, namely, nohunt junctor 320 is 'used in testing subscribers lines. When the junctor is seized relay 32I operates to ground start conductor 323 to summon an idle sender. When cross-points I36 and I32 are operated, relay I41 is operated from ground at the inner lower back contact of relay 322, re-

my 322 operating to remove this ground when relay 142 operates. A-special marker is seized andrelay 223 operated as above described. Relay 23! in the incoming frame connector passes ground back through the marker, marker connector, sender and sender link 'over the inner lower --front contact of relay 322 to the winding of relay 325 Relay 325 operates relay 235 in the incoming frame connector and connects ground over its inner lower front contact, lowermost contact of relay 231, inner contact of relay 223 to the winding of relay 226 and battery. The chief function of this relay in the marker is to suspend the terminal hunting operation so that only the particular line wanted will be seized even when it is one of a terminal hunting group. Relay 325 also opens the outgoing talking conductors and connects condenser 32B across the conductors from the marker over which the talking conductors are ordinarily tested. This is done so that the connection may be established even where the line condition is faulty.

What is claimed is:

1. In a telephone system, trunk circuits of a plurality of types, registering means, means for associating said registering means with one of said trunk circuits, means in said registering means to distinguish between types of said trunk circuits, means for controlling the establishment of connections with idle lines, other means for controlling the establishment of connections with lines whether busy or idle, means for connecting one of said control means with one of said registering means, and means in said connecting means, operated in accordance with said distinguishing means for permitting the connection of said registering means with one of said other control means only.

2. In a telephone system, trunk circuits of a plurality of types, registering means, means for associating said registering means with one of said trunk circuits, means in said registering means to distinguish between types of said trunk circuits, means for controlling the establishment of connections with idle lines, other means for controlling the establishment of connections with lines whether busy or idle, means for connecting one of said control means with one of said registering means, and means in said connecting means, operated in accordance with said distinguishing means for preventing the connection of said registering means with one of said first control means.

3. In a telephone system, trunk circuits of a plurality of types, registering means, means for associating said registering means with one of said trunk circuits, means in said registering means to distinguish between types of said trunk circuits, means for controlling the establishment of connections with idle lines, other means for controlling the establishment of connections with lines whether busy or idle, means for connecting one of said control means with one of said registering means, and means in said connecting means, operated in accordance with said distinguishing means for permitting the connection of said registering means with one of said other control means only, and means in said other control means to further distinguish between types of said trunk circuits.

4. In a telephone system, trunk circuits of a plurality of types, registering means, means for associating said registering means with one of said trunk circuits, means in said registering means to distinguish between types of said trunk circuits; "means for controlling the establishment ofcorinections with idle lines, other means for "controlling the establishment of connections with tering means, and means in said connecting means, operated in accordance with said distinguishing means for determining whether said registering means may be connected with any one of saidcontrol means or must be connected with one of said other control means only.

5. In a telephone system, operators positions of a plurality of types, each position provided with trunk circuits of a plurality of types, a plurality of types of registering means each type serving one type of operators position, means in each registering means for distinguishing between types of trunks, means for controlling the establishment of connections with idle lines, other means for controlling the establishment of connections with lines whether busy or idle, means for connecting any one of said registering means with any one of said control means, and means in said connecting means operated in accordance with the distinguishing means of a connectedregistering means for determining whether connection must be made to one of said other control means only.

6. In a telephone system, regular trunks, special trunks, connection controlling means for serving regular trunks only, controlling means arranged to' serve both said regular trunks and said special trunks, means common to said regularand special trunks for associating said controlling means with said trunks, and means in said associating means operated under the control of said special trunks to prevent said associating means from connecting a special trunk with one of said first controlling means.

'7. In a telephone system, trunk circuits of a plurality of types, registering means, means for associating said registering means with one of said trunk circuits, means in said registering means to distinguish between types of said trunk circuits, means for controlling the establishment of connections with idle lines, other means for controlling the establishment of connections with lines whether busy or idle, means for connecting one of said control means with one of said registering means, and means in said connecting means, operated in accordance with said distinguishing means to render all of said first control means artificially busy to prevent the connection of said registering means with one of said first control means.

8. In a telephone system, trunk circuits of a plurality of types, registering means, means for associating said registering means with one of said trunk circuits, means in said registering means to distinguish between types of said trunk circuits, means for controlling the establishment of connections with idle lines, other means for controlling the establishment of connections with lines whether busy or idle, means for connecting one of said control means with one of said registering means, means for normally marking said control means busy when connected with one of said registering means, and means in said connecting means, operated in accordance with said distinguishing means to render all of said first control means artificially busy to prevent the connection of said registering means with one of said first control means.

9. In a telephone system, trunk circuits of a plurality of types, registering means, means for til in control means busy to all of said connecting associating said registering means with one of means when connected with one of said registering means, and means in said connecting means, operated in acordance with said identifying means to render all of said first control means artificially busy to-the corresponding connecting means'only, to prevent the connection of said registering means with one of said first control means.

FRANKLIN A. KORN. 

